JP2002242706A - Hot water type heating device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water type heating device capable of fully heating a throttle body. SOLUTION: The hot water type heating device for an internal combustion engine has a liquid passage for heating the throttle body to prevent icing on the intake passage of the engine. Indentations is formed at the inner surface of the liquid passage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water heating device for heating an intake passage of an internal combustion engine.

[0002]

2. Description of the Related Art When an internal combustion engine is operated in cold and humid conditions, moisture contained in intake air freezes (icing) on an intake passage, which may cause engine malfunction. In order to prevent such icing, see, for example,
As disclosed in Japanese Patent No. 3164, a hot water type heating device is disposed on the throttle body to heat an intake passage such as a throttle body. In this heating device, a hot water passage through which relatively high-temperature engine cooling water flows to heat the throttle body is disposed around the throttle body. A thermo valve is provided in this passage, and when the detected temperature of the hot water in the hot water passage is equal to or lower than a predetermined value, the hot water flows through the hot water passage to heat the engine throttle body. With this configuration, when the intake air temperature is low, hot water flows through the hot water passage in contact with the throttle body, thereby heating the throttle body and the intake passage to prevent icing of the intake passage or to melt the icing. . In addition, when the temperature of the intake air becomes higher than a predetermined value, the thermo valve closes to stop heating the throttle body, thereby excessively heating the intake air heated by the heat of the throttle body. It is possible to improve the filling efficiency by suppressing the expansion of the volume of the intake air.

[0003] However, since the flow rate of hot water is controlled by a thermo valve that operates based on the temperature of the engine cooling water, the thermo valve senses the cooling water temperature after the engine is warmed up, for example, even when the temperature is extremely low. This will close the hot water passage. Then, even though the intake air is at a very low temperature, the throttle body is not heated, so that the temperature of the throttle body decreases, and there is a problem that icing in the intake passage cannot be prevented.

In order to solve such a problem, Japanese Patent Application Laid-Open No. Hei 10-317998 discloses a hot water type heating device for controlling the flow rate of hot water according to the temperature condition of intake air. This hot water type heating device has a hot water passage for heating the throttle body in order to prevent icing in the intake passage.
Further, the hot water passage is provided with a thermo valve for controlling the flow rate of the hot water by a temperature sensing part for detecting the intake air temperature. According to this hot water heating device, when the temperature of the intake air is lower than a predetermined value, the thermo valve is opened and hot water flows through the hot water passage to heat the throttle body,
When the temperature of the intake air is higher than a predetermined value, the thermo valve is closed to stop heating the throttle body, thereby suppressing the expansion of the volume of the intake air and improving the charging efficiency.

[0005]

However, in addition to the circular cross section of the hot water passage of the conventional hot water heating device described above, the size of the hot water passage cannot be increased due to restrictions on mounting on a vehicle. However, if the heat transfer area of the throttle body is small and the heat of the hot water flowing through the hot water passage is not sufficiently transferred to the throttle body, and if the temperature of the hot water is not so high, for example, immediately after starting the engine, freezing on the intake passage may occur. There is another problem that it takes time to prevent (melt).

[0006] Therefore, an object of the present invention is to provide a hot water type heating device capable of sufficiently heating a throttle body.

[0007]

According to a first aspect of the present invention, there is provided a hot water for an internal combustion engine having a liquid passage for heating a throttle body so as to prevent freezing on an intake passage of the internal combustion engine. In the heating device, an uneven portion is formed on an inner surface of the liquid passage.

According to a second aspect of the present invention, there is provided a hot water type heating apparatus for an internal combustion engine having a liquid passage for heating a throttle body so as to prevent freezing on an intake passage of the internal combustion engine. At least one protrusion extending from the inner surface of the liquid passage toward the center of the liquid passage is provided.

According to a third aspect of the present invention, there is provided a hot water type heating apparatus for an internal combustion engine having a liquid passage for heating a throttle body so as to prevent freezing on an intake passage of the internal combustion engine. A projection extends from a wall surface of the throttle body at least at a portion inside the liquid passage.

According to a fourth aspect of the present invention, there is provided a hot water type heating apparatus for an internal combustion engine having a liquid passage for heating a throttle body so as to prevent icing on an intake passage of the internal combustion engine. An insertion member having a projection on the inner surface is arranged inside the liquid passage.

According to a fifth aspect of the present invention, there is provided a hot water type heating apparatus for an internal combustion engine having a liquid passage for heating a throttle body so as to prevent icing on an intake passage of the internal combustion engine. The liquid passage is divided into a plurality of passages.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a first embodiment of the present invention; FIG. 1 is a sectional view of a hot water type heating device of the present invention provided on a throttle body. Throttle body 1 is body body 2
And a throttle valve 3. The body body 2 is made of, for example, aluminum die-cast and is substantially cylindrical.
The throttle valve 3 is for controlling the amount of intake air flowing through the intake passage 4 of the body 2 and is attached to a throttle shaft 5 rotatably arranged with respect to the body 2. The intake passage 4 communicates downstream with an intake passage of an intake manifold (not shown) and a cylinder head (not shown).

The hot water type heating device of the present invention is disposed around the throttle body 1 for heating the throttle body 1. The hot water heating device includes a cooling water supply passage 22 branched from a cooling water passage (not shown) for cooling a cylinder block and the like, a thermo valve 18 that opens and closes according to the intake air temperature of the intake passage 4, a hot water passage. 24, a hot water chamber 8 arranged in the throttle body 2, and a cooling water return passage 26 for returning cooling water to the cooling water passage.

In this embodiment, an ISC valve housing of an idle speed control device (ISC valve) (not shown) is provided on the outer surface of the body 2 (FIG. 1 shows only a portion attached to the body 2). Is attached. The ISC valve controls the amount of intake air passing through the throttle valve 3. A hot water chamber 8 is formed on the mating surface between the body 2 and the ISC valve housing 7. The hot water chamber 8 is formed by a concave portion 9 that is concave on the outer surface of the body 2. The ISC valve housing 7 has two pipe mounting holes 10 communicating with the hot water chamber 8. A connection pipe (not shown) for connecting the housing 7 to the hot water passage 24 or the cooling water return passage 26 is connected to each pipe mounting hole 10 by fitting.

The body 2 of the throttle body 1
A boss 15 is formed on the outer surface of the boss. The boss portion 15 is formed with a thermovalve mounting hole 14 that penetrates through the inside of the intake passage 4 to accommodate the thermovalve 18. Further, the thermo valve 18 is disposed slightly upstream from the closed position of the throttle valve 3 so as not to interfere with the throttle valve 3. The valve body 19 of the thermo-valve 18 has a metal temperature sensing portion containing a temperature sensing wax that expands and contracts in response to a change in intake air temperature at a tip portion (left end portion in FIG. 1) of the valve body 19. 23 are assembled. As is known, the thermovalve 18
When the temperature of the intake air detected by the temperature sensing portion 23 is lower than a predetermined temperature, a valve (not shown) is opened to connect the cooling water supply passage 22 and the hot water passage 24, and the temperature of the intake air is determined in advance. When the temperature is higher than the temperature, the temperature-sensitive wax expands, and the valve element is pressed against the spring bias via a rod (not shown) to close the valve element.

Next, the structure of the hot water passage will be described.
FIG. 2 is a sectional view of a hot water passage of the hot water heating device according to the first embodiment of the present invention. In addition to the circular cross section of the hot water passage of the conventional hot water heating device, the size of the hot water passage cannot be increased due to restrictions on vehicle mounting. Another problem is that the heat of the throttle body is not sufficiently transferred to the throttle body. On the other hand, on the inner surface of the hot water passage 24 of the present invention, for example, a projection 20 such as a female screw portion is formed, and the inner surface has an uneven shape. Since the protrusions 20 are formed in this manner, the surface area of the inner surface of the hot water passage 24 can be increased, and a larger amount of heat is transmitted from the protrusions 20 to the throttle body 2 through the hot water passage 24 than in the related art. Therefore, the intake passage 4 can be favorably heated. The position at which such a protrusion 20 is provided is
In order to transfer heat to the throttle body 2, it is preferable to be as close to the throttle body 2 as possible. Naturally, as shown in FIG. 1, even when a similar projection 20 is provided in the cooling water return passage 26, the surface area of the cooling water return passage 26 can be increased, and Since heat is transferred to the throttle body 2, as shown in FIG. 1, the surface area of the hot water chamber 8 can be increased by similarly providing the projection 20 in the hot water chamber 8 provided in the throttle body 2. As a result, a larger amount of heat can be transmitted to the throttle body 2 than in the related art.

Next, the operation of the hot water heating apparatus of the present invention will be described. During operation of the engine, when the temperature of the intake air detected by the temperature sensing section 23 is lower than a predetermined value such as, for example, 20 ° C., the thermo valve 18 is opened to prevent icing on the intake passage, and after the cylinder is cooled. Of cooling water flows from the cooling water supply passage 22 into the hot water passage 24, and returns to the cooling water passage through the hot water chamber 8 and the cooling water return passage 26.
Since the inner surfaces of these passages have a large heat transfer area as described above, a larger amount of heat is transmitted to the throttle body 1 directly or indirectly than in the prior art. As described above, since the heat transfer is performed satisfactorily, even when the temperature of the hot water is not so high immediately after the start of the engine or the like, the icing can be promptly prevented (melted).

On the other hand, when the temperature of the intake air detected by the temperature sensing section 23 is equal to or higher than 20 ° C., the thermo valve 18 closes to shut off the hot water passage 24, and the hot water passes through the body 2 of the throttle body 1, 24 and the cooling water return passage 26 are not heated. Thus, the heating of the intake air passing through the intake passage is stopped, so that the expansion of the volume of the intake air is suppressed and the charging efficiency is improved. As described above, during the operation of the engine, heat can be transmitted to the throttle body 1 better than in the conventional hot water type heating device, and icing in the intake passage can be prevented more effectively, that is, quickly (thaw). be able to.

Next, a hot water heating device according to a second embodiment of the present invention will be described. FIG. 3 is a cross-sectional view of a hot water passage of the hot water heating device according to the second embodiment. As shown in FIG.
For example, four protrusions 20 provided in the hot water passage 24 and the cooling water return passage 26 extend from the inner surface of the passage near the center of the passages 24 and 26, and extend in the longitudinal axis direction of the passages 24 and 26. With the above configuration, the passages 24, 2
The hot water at the center as well as at the periphery in the inner portion 6 comes into contact with the passage, so that heat transfer to the throttle body 1 can be performed more favorably.

Next, a hot water heating device according to a third embodiment of the present invention will be described. FIG. 4 is a sectional view of a hot water passage of the hot water heating device according to the third embodiment. As shown in FIG.
In the present embodiment, each of the two projections 20 ′ extends from the outer surface of the throttle body 1 inside the hot water passage 24 and the cooling water passage 26. With the above configuration, the passage 2
In addition to efficiently transferring the hot water passing through the projections 4 and 26 to the projection 20 ', the projection 20' is integrated with the throttle body 1 ', so that the heat transmission to the throttle body 1 is more improved. Can be done.

Next, a hot water heating device according to a fourth embodiment of the present invention will be described. FIG. 5 is a sectional view of a hot-water heating device according to a fourth embodiment of the present invention. In the present embodiment, as shown in FIG.
4 and 26, and an insertion member 30 having the protruding portion 20 and being inserted into the inner surfaces of the passages 24 and 26 are formed by different members. With the above-described configuration, not only can manufacturing be facilitated, but also the internal shape of the passages 24 and 26 can be easily changed.

Next, a hot water heating apparatus according to a fifth embodiment of the present invention will be described. FIG. 6 is a sectional view of a hot-water heating device according to a fifth embodiment of the present invention. In the present embodiment, similarly to the fourth embodiment, the hot water passages 24 and 26 and the protrusion 2
The insertion member 30 having a zero and being inserted into the inner surfaces of the passages 24 and 26 is formed by another member. The insertion member 30 is a member having a cross section. As shown in FIG. 6, the insertion member 30 can be divided into four passages by fitting to the inner surfaces of the passages 24 and 26. With the above configuration, the heat transfer area can be increased, and the distance between the hot water and the passage wall surface can be reduced, so that heat transfer to the throttle body 1 can be performed more favorably. Further, as a modified example of the insertion member of the fifth embodiment, a passage 2
When a member having a honeycomb cross section having an outer diameter equal to the inner surfaces of the inner and outer surfaces of the inner and outer surfaces is adopted, the above-described effect is further improved.

The present invention is not limited to the embodiment, and can be modified without departing from the gist of the present invention. For example, although the projections formed in FIG. 1 are provided only in a part of the hot water passage and the cooling water return passage, the projections may be provided in the entirety of these passages.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a hot-water heating device of the present invention provided on a throttle body of an internal combustion engine.

FIG. 2 is a sectional view of a hot water passage according to the first embodiment of the present invention.

FIG. 3 is a sectional view of a hot water passage according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a hot water passage according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a hot water passage according to a fourth embodiment of the present invention.

FIG. 6 is a sectional view of a hot water passage according to a fifth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Throttle body 4 ... Intake passage 20 ... Projection part 24 ... Hot water passage 26 ... Cooling water return passage

Claims (5)

[Claims] 1. A hot water type heating device for an internal combustion engine having a liquid passage for heating a throttle body so as to prevent icing on an intake passage of the internal combustion engine, wherein an uneven surface is formed on an inner surface of the liquid passage. A hot water type heating device for an internal combustion engine, wherein 2. A hot water type heating device for an internal combustion engine having a liquid passage for heating a throttle body so as to prevent icing on an intake passage of the internal combustion engine, wherein the liquid passage extends from an inner surface of the liquid passage. Wherein at least one projection extending toward the center of the internal combustion engine is disposed. 3. A hot water type heating device for an internal combustion engine, comprising: a liquid passage for heating a throttle body so as to prevent freezing on an intake passage of the internal combustion engine. A hot water type heating device for an internal combustion engine, wherein a projection extends from a wall surface of a throttle body. 4. A hot water type heating apparatus for an internal combustion engine, comprising: a liquid passage for heating a throttle body so as to prevent freezing on an intake passage of the internal combustion engine. A hot water type heating device for an internal combustion engine, wherein an insertion member having a projection is disposed on the heating member. 5. A hot water type heating apparatus for an internal combustion engine having a liquid passage for heating a throttle body so as to prevent freezing on an intake passage of the internal combustion engine, wherein the liquid passage is divided into a plurality of passages. A hot water heating device for an internal combustion engine, comprising: